1. Field of the Invention
The present invention relates to exercise equipment. In particular, the present invention relates to equipment for therapeutic exercise of leg muscles.
2. Discussion of Background
There has been a rapid growth in the number and types of exercise equipment in the recent past, paralleling interest in exercise generally. Exercise is also an important part of therapy, following an injury or illness. The leg muscles are large muscles and an especially important muscle group. Working the leg muscles is usually key to exercising aerobically as well as to standing and walking.
A number of devices exist that exercise muscles of the upper leg: the quadriceps, the hamstrings and the gluteal muscles. See for example the leg exercising device of Brentham in U.S. Pat. No. 4,247,098 which requires a user to lift the thigh against a resistance load provided by an hydraulic cylinder. A much different device is disclosed by Roman in U.S. Pat. No. 4,229,001. Roman's therapeutic exerciser for the leg is a boot-like device mounted on a pair of rails. The device is useful for knee bending exercises in which the boot is moved from a leg-bent position to a leg-straightened position against a resistance provided by springs in the rails.
The device of Bierman, described in U.S. Pat. No. 2,542,074, comprises a frame with a load attached via a cable and pulleys to a pivotable foot rest. Movement of the foot in exercising the lower leg muscles is against the load.
None of these devices, however, exercises the muscles of the leg by applying a load directly to the posterior aspect of the knee.